Money belts are well known. They consist of a closable holder with one or more compartments. They are generally elongate with a belt portion at opposed short ends for wearing around the waist beneath the clothing. This provides a very secure location, not visible to passersby. However, the belt directly against the body may be uncomfortable. Furthermore, access is extremely awkward.
More accessible are the pouches that mount directly by a short strap onto the belt that supports the trousers or skirt. These advertise to the passerby exactly where to go for the valuables, so they may be an invitation to crime against the person and property. Furthermore, they bulge outward from the trousers, giving an unattractive appearance. They cannot be readily moved from a concealed position under the trousers to an accessible position in front of the trousers.